def __init__(self, bytecode, pc, nstack, blockstack):
"""
Parameters
----------
bytecode : numba.bytecode.ByteCode
function bytecode
pc : int
program counter
nstack : int
stackdepth at entry
blockstack : Sequence[Dict]
A sequence of dictionary denoting entries on the blockstack.
"""
self._bytecode = bytecode
self._pc_initial = pc
self._pc = pc
self._nstack_initial = nstack
self._stack = []
self._blockstack_initial = tuple(blockstack)
self._blockstack = list(blockstack)
self._temp_registers = []
self._insts = []
self._outedges = []
self._terminated = False
self._phis = {}
self._outgoing_phis = UniqueDict()
self._used_regs = set()
for i in range(nstack):
phi = self.make_temp("phi")
self._phis[phi] = i
self.push(phi)
def run(self):
"""Run a trace over the bytecode over all reachable path.
The trace starts at bytecode offset 0 and gathers stack and control-
flow information by partially interpreting each bytecode.
Each ``State`` instance in the trace corresponds to a basic-block.
The State instances forks when a jump instruction is encountered.
A newly forked state is then added to the list of pending states.
The trace ends when there are no more pending states.
"""
firststate = State(bytecode=self._bytecode,
pc=0,
nstack=0,
blockstack=())
runner = TraceRunner(debug_filename=self._bytecode.func_id.filename)
runner.pending.append(firststate)
# Enforce unique-ness on initial PC to avoid re-entering the PC with
# a different stack-depth. We don't know if such a case is ever
# possible, but no such case has been encountered in our tests.
first_encounter = UniqueDict()
# Loop over each pending state at a initial PC.
# Each state is tracing a basic block
while runner.pending:
_logger.debug("pending: %s", runner.pending)
state = runner.pending.popleft()
if state not in runner.finished:
_logger.debug("stack: %s", state._stack)
first_encounter[state.pc_initial] = state
# Loop over the state until it is terminated.
while True:
runner.dispatch(state)
# Terminated?
if state.has_terminated():
break
elif (state.has_active_try()
and state.get_inst().opname not in _NO_RAISE_OPS):
# Is in a *try* block
state.fork(pc=state.get_inst().next)
tryblk = state.get_top_block('TRY')
state.pop_block_and_above(tryblk)
nstack = state.stack_depth
kwargs = {}
if nstack > tryblk['entry_stack']:
kwargs['npop'] = nstack - tryblk['entry_stack']
handler = tryblk['handler']
kwargs['npush'] = {
BlockKind('EXCEPT'): _EXCEPT_STACK_OFFSET,
BlockKind('FINALLY'): _FINALLY_POP
}[handler['kind']]
kwargs['extra_block'] = handler
state.fork(pc=tryblk['end'], **kwargs)
break
else:
state.advance_pc()
# Must the new PC be a new block?
if self._is_implicit_new_block(state):
state.split_new_block()
break
_logger.debug("end state. edges=%s", state.outgoing_edges)
runner.finished.add(state)
out_states = state.get_outgoing_states()
runner.pending.extend(out_states)
# Complete controlflow
self._build_cfg(runner.finished)
# Prune redundant PHI-nodes
self._prune_phis(runner)
# Post process
for state in sorted(runner.finished, key=lambda x: x.pc_initial):
self.block_infos[state.pc_initial] = si = adapt_state_infos(state)
_logger.debug("block_infos %s:\n%s", state, si)
def __init__(self, bytecode):
_logger.debug("bytecode dump:\n%s", bytecode.dump())
self._bytecode = bytecode
self.block_infos = UniqueDict()